This invention relates to a solid state imager assembly and, in particular, to a highly compact imager assembly suitable for use in a video endoscope.
The increased availability of smaller solid state imagers based on CCD or CMOS technologies has surpassed the ability of conventional wire bonding techniques to take full advantage of the space savings afforded by these small imagers. An advanced integrated circuit technology known as the tape automated bonding (TAB) process has been developed which permits fine line high pitch lead patterns to be bonded to extremely small electronic components such as CCD imagers. In this process the imager is supported on a thin flexible substrate and the high density imager leads are TAB die bonded to the substrate. The high pitch leads typically extend outwardly from both sides of the imager for a distance sufficient to allow the leads to be connected to other electrical components using more conventional bonding techniques. A transparent window, typically being glass, is placed over the imager and the extended leads to complete the package. This package will be herein referred to as a TAB imager or TAB imager package.
TAB packages are structurally relatively weak and are normally mounted on a flat support such as an IC board, along with other electrical components. The TAB boards, however, are rather bulky and space consuming and thus do not lend themselves for use in confined regions such as in the camera head of a video endoscope.